Air conditioner



June 16, 1%36. R|HTER 2,044,33Q

AIR CONDITIONER Filed March 6, 1955 2 Sheets-Sheet 1 June 16, 1936. A, RICHTER 2,044,33G

AIR CONDITIONER Filed March 6, 1933 v 2 SheerLs-Sheet 2 Fig.5 Fig.6

Patented .Fe 16, 1936' l s s- (cr es-ire) (Gran under the pro oi? use. is. not oi I March 2, 1927: 3'80 0.6.

process is applied to cool or heat only one room.

The process is essentially based on the suitable use of an appropriate heat-exchanger for the transmission oi heat of a cold air machine of open" cycle type in such a way that for the heatabstraction and. absorption no special heating or cooling bodies are necessary; the heat-abstraction and absorption take place by means or mixing with the air of the room atmospheric air.

The process according to the invention further more is based on the fact that the steam contained in the air is also made efiective for the transmission of heat, simultaneously avoiding re= duction in emciency of the cold air'machine by the presence of atmospheric moisture.

In the drawings several u cuts are shown for carrying out the new process, in which:-

Fig. 1 is a diagrtic vertical sectional view of one embodiment.

Fig. 2 is a cross sectional detail view through the piston-like body of the heat-exchanger in the course of formation.

Fig. 3 is a similar view showing the same when completed.

Fig. 4 is an enlarged side elevational detail partly in section of the same.

Figs. 5 and 6 are diagrammatic longitudinal sectional views of a further embodiment of the device for carrying out the process, and

Figs. 7 and 8 are similar views on a reduced scale corresponding respectively to Figs. 5 and 6 showing the parts at difierent cycles of their 0 eration.

This heat-exchanger is adapted to absorb heat and moisture from an air-"current and to transmit them later to another air-current. For thispurpose it is desirable that the heat-exchanger utter a large surface of contact to the air-current. This is obtained by forming the heat-exchanger (t) of an aluminium toll of a thickness of about 0.1 to 0.2 mm. and by winding along band of this foil spirally around the axis (0) asshown in Fig. 3. For this purpose any other metal may also be used which isadapted to be hammered or rolled to foils, such as tin, copper and the like. But aluminium is especially suitable in view of its dotted line.

great w- ;t. conductivity and heat capty. Between the single windings, bands (to) e of any solid material are inter ii in such a way that many 11 flat channels are built, through which air-currents are later led. Furthermore the heat-exchanger is divided by incisions (a) into several zones (0). By this device it is possible to put in a simple wav a large surface oi contact in a relatively small apparatus. Fig. 1 shows an air compressor (a) with rotating piston, an expansion cylinder (b) with rotating piston, and two valve housings (d and e), in each of which is placed a piston-like body (t), (t) constitut ing a heat-exchanger oi the type as shown in Figures 3 and 4. The chambers (f. 9 and h) are connected by means of ports with the piston valve housings. The two piston valves (t and t) are coupled by means ot a crank drive (i and ii) in such a way that they reciprwat'e in opposite directions. The device represented in Fig. l is wed to cool a room A, which is shown by the The other roorr B is to be taken as exterior atmosphere. As i' that this atmosphere shows a temperature f +10 0.; the mode of operation is the following:

The rotating piston (l) in the air compressor (a) draws atmospheric air through the channel (m) and compresses it intothe chamber (1') under an increase of pressure of 0.5 atm. so that the total pressure of the air contained in the chamber (f) amounts to 1.5 atm. The temperature of this compressed air has been in- 1.5M according to the eflect oi the compression from +10 C. to +45 0. This compressed and heated air sea in the direction oi the arrow through a channel into the valve housing Te), then through the many s channels of the heat-exchanger (t) and enters the chamber (9'). Assu that this heat-exchanger (t) shows in the foremost zone a temperature of about +d8 C. and in the last zone a temperature of about 0 0.: The air therefore, while r. through the heat-exchanger (1), will transfer a part of its heat to the material of the heat-exchanger in the single zones thereof and after attaining the saturation point will also preclpitate atmospheric moisture in the form of dew.-

g. The pressure in the chamber 9 is only a little lower than in the chamber (according to the resistance to flow) and amounts approximately to 15 atm. The air now passes into the expansion cylinder-(b) and pushes the piston (1!) forward in the direction of the arrow, whereby the air expands while performing work and passes in the direction of the arrow into the channel (q) When passing into the channel (q) the air is reduced to atmospheric pressure and as a result is reduced to a very low temperature, whichconsidering the losses in the walls and the likeamounts to about 25 C. This cold' air passes from the channel (q) to the cooling room A, thereby again absorbing heat from the chilled p'roducts contained therein and from the walls and warming up to a temperature of. about 2 C. By the absorption of the heat the purpose of the cooling has been attained, as the chilled products in the room A and the air of this room have been cooledaccordingly. Of course the cold air which passes out has mixed with the air of the cooling room. I

A corresponding part of the air of the cooling room now passes throughthe channel (1') to the chamber (h) as shown by the dotted lines, which represent the prolongation of the channel (1').

From the chamber (71.) the air passes in the direc temperature of 0 C. in the foremost chamber and a temperature of +44 C. in the last chamber: The air therefore will absorb a part of the heat accumulated in the material of the heat-exchanger (ti) while passing through it; thereby it is warmed up so that it passes out at a final temperature of about 42 C. On its way through the heat exchanger (t1)-due to its warming upthe air shows a great saturation capacity, by which the moisture contained on the material of the heat-exchanger as dew evaporates and the steam-content of the air is increased.

At the above mentioned mode of operation the material of the heat-exchanger (1!) naturally will warm up a little and the material of the heatexchanger (t1) will cool downa little. In order to avoid a further warming up or cooling down, which would reduce or annul the efficiency of the process, the two piston valves (t and t) are brought into inverse position by turning the cranks (i and i1). By this displacement the inlet and the outlet ports on the left as well as on the right side are exchanged accordingly so that in the further course the heat-exchanger (t) takes up the function of the heat exchanger (t1) and vice versa. From this reversing results that the heated air is led through the valve housing (11) and the air leaving the cooling room A namely, the chamber (b) through the valve housing (e). By this reversing the direction of the air current in each heat-exchanger is inverted, the material of the heat-exchanger (t) is cooled down again and the material of the heat-exchanger (ti) warmed up again accordingly. The

reversing of these two piston valves is carried out continuously in short periods (about 30 times per minute). Therefore hot and cold air passes alternately in countercurrent through each heatexchanger, the air of the two air-currents always coming'into contact with the same surfaces of the heat-exchanger. This is of special importance as only by the described mode of operation the moisture precipitated by the air-current which is cause only a small part of the refrigeration output cooled down is dried by the following air-current, which is warmed up.

As the hot current of compressed air is cooled down to about 0 C. when leaving the heat-exchanger, it has only a small content of steam, about 5 grams/m the greater part of the moisture originally contained in the atmospheric air (about 17 grams) has been delivered to the surface of the heat-exchanger as precipitate. As the steam content of the compressed air precooled to about +2 C. is only very small, the drop in temperature caused by the release becomes nearly .completely active at the following release for the effective refrigeration output beis consumed for the condensation of the rest of the existing steam.

The working of the compressor (a) and of the expansion cylinder (b) takes place continuously; only the air-current itself is led periodically through the valve housings (e and d) so that the released air-current leaving the cooling room through the valve housing (d) passes through the adjacent port into and through the channel (s) into the atmosphere while simultaneously the compressed air-current passes through the valve housing (e) and vice versa.

By the described mode of operation of the process heat and moisture have been brought from the cooling room (A) into the exterior atmosphere (B). -As the temperature in the room (A) amounts to about 2 C. it was necessary to raise the quantity of heat 'to the temperature of the exterior atmosphere. The expenditure of energy necessary for this purpose has been spent by the work done in driving the piston (l) in the air compressor (a). Naturally theexpenditure of energy in the compressor (a) was still greater than'it would have been necessary for the transmission, but a part of this spent energy is recovered by the output of the air in the expansion cylinder (b) so that only the difference of energy to overcome the drop in temperature was necessary. It is of advantage to mount the piston of the expansion cylinder on the same axis as the compression cylinder in order to get the best possible recovery of energy and to avoid all avoidable losses by friction.

In the above description of the function it has been assumed that the heat-exchangers (t and 5 t1) show a certain specific temperature in the single zones. In order to obtain this specific temperature the flap valve (1)) is closed'at the beso that a part of the cold air passes into the cooling room (A) while only a part of the cold air directly into the channel (1'). When the cooling room has reached the desired temperature (about 0 C.) the flap valve (12) may be completely opened so that the total refrigeration output is available for the cooling room. The process of precooling is essential because the greater part of the moisture of the air is de 75 aosasso coming relatively high drops in temperature by small pressure difierences of the air. Flu-thermore small tensions enable an easy 1: tight of the single moved parts and result-in a high efiiciency.

On account oi the small pressure difference the desired results may also be obtained without using the adiabatic expansion for recovering of power, whereby the construction of the expansion cylinder is materially simplified. In this case the loss of power will be comted for by the simplification of the design.

Apart from the two piston valves the whole process does not need any valves or control gears and it is easily possible to carry out the process up to the greatest outputs. Of course it is possible to use a turbo-blower or the like instead of the rotating pistons. The process is also applicable for lower temperatures with good efficiency. The omission of the transmission elements (cooling and heating bodies viz. condensers) is a further important advantage of the invention.

In the above description the process has been shown when carried out for the cooling of a cold storage room, which is used for keeping food or the like. The process and the described device can also be used for heating rooms. Then the provided room (A) takes the place of (B) and heated air enters the latter. The heat conveyed to the room then is taken from the exterior atmosphere. Thereby it is possible to carry out this process with materially increased heat out-.- puts per kilowatt hour compared with the hitherto known resistance heaters. Especially will such a heating process as given by the invention yield better results when applied to vehicles such as railways where a source of electricity is available for heating.

Figs. and 6 show a further device for applying the process; a combined system of cylinders with moving pistons is used for conveying the air. The piston valve housing (he) is vided and furnished with two heat-cancers (is and ta). 1

The mode of operation on an ave is the same as described in connection with Fig. l. The subdivision of the piston valve and the corresponding other position of the air channels are new and carried out in such a way that only the compressed and superheated air flows, b. both heat-exchangers (ta and t2) succveLv, the air leaving the cooling room w only through the heat-exchanger (t2) The re-cooling oi the heat-exchanger (t takes place in such a way that atmospheric air is sucked in by a special purging piston and is p again through the heat-exchanger (t3). The device substantially consists of a chamber (2i in which atmospheric air is contained. To this clmmber' (z) a compressor (a) is mounted. Furthermore the device consists of a chamberix) and the expansion chamber (y). Y

The mode of operation of the with this device is the following:

In Fig. 5 the piston valve controlledby the crank (dz) has reached the u posil (f1) and further into the i'reeatmosphere.

tion. nks (is. dads) mounted on a common ems and move in the direction oi the arrows. The crank (414) has driven the compressor piston (or) upward and thereby compressed the air enclosed in the chamber (a) to about 1.5 5 atm. The chamber (a) communicates through the channels (/1, is, I: and f4 asshown by the arrows) with the chamber (11) in such away that also in the chamber (1:) there exists a pressure of 1.5 atm. By the fer rotation of the crank-shaft the piston-rod (g3) is driven up ward and the compressed air contained in the chamber (2) is pressed through the channels (h to It) into the cber (y). Apart from .the friction there, is no special power required, 15

as the piston (ha) the t speed as the piston (he) and the volume of the chamber (y) increases proportionately to the decrease of the volume in the chamber (a) u compressed air has cooled down accordingly on the way through the heat-exchangers (t3 and ta).

In Fig. 7 the final state of the above described period is represented; that is, the greater part of the compressed air it passed from the chamber (a) into the chamber (y). At the next rota- 2 tion of the crank the travels (ii to f4) for the 1: (e, y) are closed by the piston valve (b2).

In Fig. 6 the further period after the rotation of the crank is represented. The piston valve (be) now reached its lowermostpos ition. A further rotation of the ck-shaft results in moving the piston rod (or) downward, whereby the volume of the m (y) is reduced and the air contained therein; which has already been released through the opened channel, passes into the outlet branch (82).

By moving the piston (ha) downward air from the cooling room is sucked in through the channels (me, it, is) into the chamber (a). The cyii0 lnder space of the compressor (22) is filled with air from the cooling room. Due to the pge of the cooling room air through the. heat-exchanger (is), the cooling room air entering the chber (s) has warmed up from about 0 .C. to about +lil".

Morn Fig. 8 the further course of the piston position is evident. The chamber (2) then has attained its greatest volume and the released air is removed to a large extent from the chamber (y). it followsnow the period shown in Fig. 5, in which by the moving upward of the piston (@z) in the compressor the air in the 0:1 (2) is compressed to about 1.5 atm., a new action of it pistons being started. After compressing the air in the chamber (a) it is pressed into the chamher (3!) and released there. finally leaving for the cooling room. During the action in the 11; m (z, y) the iollog process has taken place simultaneously in the chamber (:2).

At the period represented in Fig. 5 the piston rod (92) is moving upward. The chamber (2) is filled with atmospheric through the channel opening (an). In order to enlarge the chamber (a) the room (an) placed beneath the piston (ha) 2.. been made available; bymoving the piston (he) upward also the volume of the chamber (an) is increased. The chamber (:82) communicates with the chamber (2) by means of a connecting cel. By the downward movement of the piston rod (gr) (as shown in the period according Fig. 6) the atmospheric air contained in the chbers (a: and am) (called rinsing air) is -.-1 through the channel (is) to the e1? passing through the heat-exchanger (ta) the atmospheric rinsing air has cooled down the material of the heat-exchanger according to the requirements of the present invention so that during the following period the heat-exchanger is capable of again absorbing heat, which has to be abstracted from the hot compressed air current.

The flap valve (it) has the same function as the flap valve (12) already described in Fig. 1. In the same way also the other proceedings concerning the giving off and taking up of the heat is shown also in Figs. 5-6 by arrows.

As evident from the modesof operation described above in Fig. -1 for carrying out the cyclic process, fresh atmospheric air and a corresponding quantity of cooling room air have been exchanged continuously in such a way that simultaneously with the cooling an intensive ventilation of the cooling room takes place without needing a special refrigeration output for this purpose.

If a ventilation is undesirable the mode of operation as shownin Figs. 5 and 6 may be used, as then only cooling room air is working in the cyclic process and the atmospheric air is used as so-called rinsing air only for abstracting heat.

To sum up: The invention concerns a cooling and heating process which is based on the recognition that the energy lost by the condensation of the steam contained in the air to be cooled can be recovered (to a large extent) by changing periodically the ways of the two air currents passing between the cold and the warm room, thereby recovering for the purpose of heating the energy lost by condensation while cooling. The

invention furthermore concerns devices ifor carrying out this process and more especially a heatexchanger, which is built in a special way of suitable material.

I claim:

1. Process for cooling and heating air in an open cycle, one air-volume being cooled and. another air-volume separated from the first one being heated, which comprises compressing air from the volume to be heated, cooling the compressed air, thereby condensing the moisture contained therein, expanding this air when entering the other volume, simultaneously leading from the cooled volume into the volume to be heated air which is heated by contact with condensed water of higher temperature and periodically changing the direction of flow of the air currents in such a way that the directions of flow of the two air currents are altered periodically, so that the,

cooled which takes up part of the heat deposited by the first air current and simultaneously providing current of air from the volume to be heated flowing again into this volume, which current takes up the rest of the heat and the moisture deposited by the first air current.

3. A device of the character described comprising at least one compressor cylinder, an expansion cylinder, two heat-exchangers including a housing having inlet and outlet ports and a piston body in the housing and composed of a metal foil wound into a cylindrical form and spacing elements between each single winding to provide a plurality of small channels therein. the piston body being adapted to be shifted axially in the said housings thereby governing the ports in the housings, means tor shifting the piston bodies in their housings, pipes establishing communication between the compressor cylinder and the ports in the heat-exchanger housings and between'the latter and the expansion cylinder, pipes establishing communication between the room to be heated and the ports in the heat-exchanger housings and between the latter and the room to, be cooled.

4. A device of the character described comprising at least one compressor cylinder, an expansion cylinder, two heat-exchangers including a housing having inlet and outlet ports and a piston body in the housing and composed of a metal foil wound into a cylindrical form and spacing elements between each single winding to provide a plurality of small channels therein, the piston body being adapted to be shifted axially in the said housings thereby governing the ports in the housings, means for shifting the piston bodies in their housings, pipes establishing communication between the compressor cylinder and the ports in the heat-exchanger housings and between the latter and the expansion cylinder, pipes establishing communication between the room to be heated and the ports in the heat-exchanger housings foil wound into a cylindrical form and spacing elements between each single winding to provide a plurality of small channels therein, each body having incision cuts forming. an angle of 90 with the axis of the windings, the piston body being adapted to be shifted axially in the said housings thereby governing the ports in the housings, means for shifting the piston bodies in their housings, pipes establishing communication between the compressor cylinder and the ports in the heat-exchanger housings and between the latter and the expansion cylinder, pipes establishing communication between the room to be heated and the ports in the heat-exchanger housings and between the latter and the room to be cooled. I

6. A device of the character described comprising at least one compressor cylinder, an expansion cylinder, two heat-exchangers including a housing having inlet and outlet ports and a piston body in the housing and composed of a metal foil wound into a cylindrical form and spacing elements between each single winding to provide a plurality of small channels therein, each body having incision cuts forming an angle of 90 with the axis of the windings, the piston body being aoeasso adapted to be shifted axially in the said housings thereby governing the ports in the housings, means for shifting the piston bodies in their housings, pipes establishing communication between the compressor cylinder and the ports in the heat-exchanger housings and between the latter and the expansion cylinder, pipes establishing communication between the room to be heated and the ports in the heat-exchanger housings and between the latter and the room to be cooled. and a valve in the outlet of the expansion cylinder.

7. A device of the character described. comprising a compressor cylinder, an expansion cylinder, two surface heat-exchangers having a large surface, channels and valves at the inlet and outlet ends of the said heat-exchangers adapted for the communication of the outlet ends of the said heat-exchangers with the inlet of the said expansion cylinder and alternately with the space into which the outlet end of the said expansion cylinder opens, and for the communication of the inlet ends of the said heat-exchangers with the outlet of the said compressor cylinder and alternately with the space from which the said compressor cylinder sucksthe said valves being adapted to form alternately one of the said heatexchangers as communicating channel between the compression space of the said compressor and the expansion space of the said expansion cylinderwhile the other heat-exchanger simultaneously serves as communicating channel between the outlet chamber of the expansion cylinder and the inlet chamber of the compressor cylinder.

8. A device of the character described, comprising a compressor cylinder, an expansion 'cylinder, two surface heat-exchangers having a large surface, channels and valves at the inlet and outlet ends of the said heat-exchangers adapted for the communication of the outlet ends of the said heat-exchangers with the inlet of the said expansion cylinder and alternately with the space into which the outlet end of the said expansion cylinder opens, and for the communication of the inlet ends of the said heat-exchangers with the outlet of the said compressor cylinder and alternately with the space from which the said compressor cylinder sucks, the said valves being adapted "to form alternately one of the said heat-exchangers as communicating channel between the compression space .of the said compressor and the expansion space of the said expansion cylinder while the other heat-exchanger simultaneously serves as communicating channel between the outlet chamber of the expansion cylinder and the inlet chamber of the compressor changers.

cylinder, three devices for reversing the said heatexchangers and a throttle in the outlet channel of the said expansion cylinder.

9. A device of the character described, comprising a compressor cylinder, an expansion cyl- 5 heat-exchangers with the inlet of the said ex- 10 pansion cylinder and alternately with the space into which the outlet end of the said expansion cylinder opens, and for the communication of the inlet ends of the said heat-exchangers with the outlet of the said compressor cylinder and 15 alternately with the space from which the said compressor cylinder sucks, the said valves being adapted to form alternately one of the said heatexchangers as communicating channel between the compression space of the said compressor and go the expansion space of the said expansion cylinder while the other heat-exchanger simultaneously serves as communicating channel between the outlet chamber of the expansion cylinder and the inlet chamber of the compressor cylinder, gs

each of the said heat-exchangers including a body composed of a metal foil wound spirally and spacing elements between all the windings for forming a plurality of narrow channels therein.

'10. A device of the character described, comso prising a compressor cylinder, an expansion cylinder, two surface heat exchangers having a large surface, channels andvalvesat the inlet and outlet ends of the said heat-exchangers adapted for the communication of the outlet ends of these said heat-exchangers with the inlet of the said expansion cylinder and alternately with the space intowhich the outlet end of the said expansion cylinder opens, and for the communication of the inlet ends of the saidheat-exchangers with the outlet of the said compressor cylinder and alternately with the space from which the said com-" pressor cylinder sucks, the said valves being adapted to form alternately one of the said heatexchangers as communicating channel between the compression space of the said compressor and the expansion space of the said expansion cylinv der while the other heat-exchanger simultaneously serves as communicating channel between the outlet chamber of the expansion cylinder and the inlet chamber of the compressor cylinder, the said valves consisting of piston valves which are adapted to receive the said heat-exmm atom. 

